This invention relates to a device for sealing a clearance between two relatively moving surfaces, particularly a radial end face of a roll in a fiber processing machine and an adjoining stationary wall face forming part of the machine (such as a card, a roller card unit, a card feeder or a cleaner).
It is generally difficult to seal relatively movable surfaces against one another. Such is the case when a seal has to be provided between a radial end face of a rotary roll or cylinder and an adjoining wall surface. It is known, for example, to use squeegee-like devices which, however, have not proven to be satisfactory. The principal difficulty in fiber processing machines resides in the fact that air circulations in the clearance lead to undesired fiber movements. Thus, very small fiber fragments gain access to the clearance in which they may accumulate which, in the long run, leads to clogging or significant braking of the roll. For preventing fiber particles from entering into the clearance, bristle seals have been used. These, however, have also not proven successful because they were either too stiff or too loose and thus have led either to a braking of the roll accompanied by significant frictional heating or have not provided an acceptable seal at all. It is a also a disadvantage of known sealing constructions that in case of a periodic engagement of the seal, a "breathing motion" between the space to be sealed and the external environment occurs.